DE1961725A1 - Circuit arrangement for the automatic checking and determination of faults in the subscriber groups of a time division multiplex switching system - Google Patents

Description

198172S

8082-69 / H

DB 181

No. 25 065 Δ / 68

d.d.p. U. 12.1968

LAB. SS

SOCIETA ITALIANA TELECOMUNICAZIONI SIEMENS spa, Milan,

Italy

Circuit arrangement for automatic checking and Detection of disturbances in the subscriber groups of a time division multiplex switching system

The invention "relates to a circuit arrangement for automatic checking and detection of malfunctions in the subscriber groups of a Zeitraultipiex telephone exchange, which has two circulating memories in a central operating unit, which contain the number of the calling or that of the called subscriber and save the Closure of the subscriber group with a common voice line and a common signaling line connecting switch control, and which further includes a generator that a hoof current to all subscriber circles common ringing current line sends the subscriber: iron is supplied via a separate switch.

In particular, the invention relates to an electronic circuit arrangement which successively checks all subscriber groups connected to a Zeitinul tipi ex switching system and isolates the defective or disturbed subscriber groups if the malfunction disrupts the operation of the

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affect central units of the switching system would.

In time division multiplex telephone exchanges, which are known work with electronic switches and control devices, there is the problem that occurring Disruptions can affect the entire operation of the switching system. Such serious malfunctions are not only limited to the centralized operating unit of the switching system which is the connection or ^ Controls switching processes, but they can also occur in the external part of the switching system that comes from the The entirety of the subscriber groups consists of · This is because all subscriber groups through a switch to one single voice line can be coupled, so that the wrong actuation or failure of one of the switches can interfere with the entire voice line · In addition, the subscriber signaling currents also arrive from each subscriber group on a common signaling line and An error in one group of participants can affect the entirety of the information.

There are already devices for solving similar problems W me known to electro-mechanically operating switching systems that are their structure after unsuitable for an electronic system. Similar to these devices, however, cyclical scanning of all participants can be carried out. For this purpose, suitable test signals can be sent and the results checked.

The test device must perform the following operations:

1) Selection of the group of participants to be tested and the broadcast the test signals j

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2) checking the effect of the test signals;

3) Isolation of the groups of participants in which there is a disturbance or a damage is found which affects the operation of the central units of the switching system can.

When sending the test signals, it is desirable that these are as far above the switches as possible get into the group of participants, and if possible already at the subscriber line, so that a simulation of the Speech signals as well as the two-line signaling stream ("Stream of the Two Lines") is as real as possible.

A circuit arrangement according to the invention is used in an electronic which operates on the time division multiplex principle Switching system used in which the distribution of the ringing current to the subscriber lines made by circuits independent of the voice line and the signaling line · The electronic ones Switches that couple these lines with the participants are not able to to carry the call current of normal strength. The Rufstronsehaltkreise are usually formed by mechanical switches that operate the primary winding of the transformer of the Coupling subscriber group with a common line on which a generator sends the ringing current and the following Ringer line is called. If no participant requests the transmission of the ringing stream (a corresponding Information is given by the aforementioned central operating unit) the ringing current generator is supplied by the ringing current line decoupled and this is instead »connected to a generator for the test signals.

The test signals are transmitted through a single audio frequency

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signal that is used directly to simulate the Speech signals is used, and which can be interrupted in such a way that with the negative wavefronts or signal edges the changes in the (two-wire) Signaling current is simulated.

A test unit used to advance a test program selects the group of participants to be tested by incrementing a counter at the end of each test cycle, in which this results in successive form the numbers of the groups of participants. The test unit also controls the transmission of the test signals by the test signal generator and in accordance with a service time channel (hereinafter referred to as channel h) the closing and opening of the switch of the group of participants to be tested, which this group of participants connect to the ringing line, the voice line and the signaling line.

The test unit also compares the results of the test tests with the signals sent, and if it finds that they do not match, it generates a Alarm signal, specifically for various test attempts correspondingly different alarm signals generated. The information about the test results are sent to the test unit in the form of binary signals from a Receiving unit that transmits the signal level the voice line and on the signaling line. This control is carried out on the voice line not only in time channel h, but also in the following time channel, so that hypocritical effects can be determined.

In a practical embodiment of the invention, the test unit is not completely controlled by the central control

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drive unit of the switching system separated, since ea It is possible and expedient to use some circles of the operating unit for the test unit as well. Normally have electronic time-sharing switching systems to control the switches of the subscriber groups via two circulating memories, one of which is for storage the numbers of the calling subscribers and the other for storing the numbers of the called subscribers serves. Control of the switches through this memory

about
done / decoder. Certain phases in both memories are intended for the "services ¹ · of the switching system · One of the service phases, which corresponds to the time channel h, is used together with an additional logic circuit to implement the counter that is required to select the subscriber groups one after the other.

The test unit also contains a logic combination circuit, dia is used to check or control the sequence of the various test attempts. Also for this A phase (h) of a circulating memory can be used as a memory in the switching system already exists and has other functions to perform.

In order to isolate defective subscriber groups if the disturbance endangers the operation of the entire switching system, the totality of the subscriber groups must be divided into individual * 3 groups. Within each group, the subscriber groups are connected to a speech signal conductor and a separate conductor for the subscriber signaling, which in turn are coupled to the common speech line or signaling line via isolating switches. For everything in

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1961723

In large communication systems, for various other reasons, the subscriber groups are often already divided into groups that are connected to the common lines of the communication system via a group switch. These switches can expediently be used as isolating switches if the circuit arrangement used to detect faults controls the transmission of the signals with which the central operating unit causes these switches to close. For this purpose, the circuit arrangement according to the invention preferably contains a blocking unit which, based on the alarm signals supplied by the checking unit, sends a blocking signal to the central operating unit, which interrupts or suppresses the command signals for closing the disconnectors in the respective group of subscribers being checked. However, this only happens if a fault occurs that could endanger the operation of the entire switching system.

The blocking unit contains a storage circuit for each subscriber group for storing the blocking information, i.e. information about the prevention of the closing of the switches "This means that any alarm signal that may occur is allowed to pass through if it is a signal that causes a disturbance that can be seen in other circuits of the ¥ erml / ti-

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treatment system could spread. This alarm signal determines the keying in of the locking information into the memory circuit.

The invention will now be explained in more detail with the aid of the drawing. The drawing shows in »

1 shows a schematic circuit arrangement according to the invention;

2 shows an embodiment of a test unit; and 3 shows an embodiment of a locking unit.

In the electronic tent multiplex switching system shown in FIG. 1, subscriber groups Ay ₁ ... AjJ ₂ J "belong to which corresponding subscriber sets U ... U". are assigned to a single group (generally denoted by h) which is connected to a group voice line V. and a group signaling line V ₈ J ₁ . The speech line and the signaling line of all subscriber groups are to a central speech line V_ and a central signaling line

egg

connection V of the switching system. In each subscriber group there is a switch I ″, via which voice current samples reach the voice line V-, and a switch I, via which subscriber signaling samples detected by a threshold value detector Riv reach the signaling line Y _gh. The ringing current is sent from a generator GC to the ringing current line V _c and can reach the desired subscriber via a switch I _5. The electronic switches I ^, Ig and I- in each subscriber group are controlled by a central operating unit UG. This company

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196 ms

unit receives the subscriber signaling via the central signaling line and controls that of all subscriber lines which are connected to this signaling line are connected via a time channel, transmitted information

The test circuit according to the invention contains a test signal generator GH, which then Eit the ringing current line V is coupled when the transmission of the ringing current to a subscriber is not required. The test

P signals reach the participants via the switch I-ι through which the ringing current normally flows · The test extends to both madness of the current path of the speech currents of the subscriber to be tested up to the speech line V_ as well as to the Completeness of the current path of the subscriber signaling up to the signaling line V. The test signals simulate the sound or speech signals coming from the subscriber group and also the "Zweileitungs" -Signalisiertmgsstroffi. They are formed by a single tone of 800 Hz produced by the generator GH and via switch I, (the mode of operation of which will be explained later) and a coupling condenser

™ tor C reaches the secondary winding of the input transformer T of the subscriber circuit. Here the 800 Hz tone cannot be distinguished from a real tone signal coming from the subscriber line . 800 Hz - Tones are simulated, the negative wave fronts or planks of which are viewed by the detector RIv as changes in the state of this current.

A receiver RIc 1 is used in a receiving unit BR to determine the presence of the signal, dae the signaling eetrom on the signaling line V

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simulated. Another receiver Eic 2 detects the presence of the 800 Hz tone signal on the voice line V ₀ . The same 800 Hz signal also serves

el

for checking whether crosstalk effects occur. For this purpose, a third receiver Ric 3 scans the voice line V _e in accordance with the time slot

Gk

02, which follows the time channel Ci, on which the receiver Rio «works. The signal level determined by the receiver Rio is compared in a comparison stage CB with the maximum permissible crosstalk level which is supplied by a generator SO. The results of the test tests, which are contained in the output signals S ^, S ₂ and S- of the receivers RiCj and Ric "or the comparison stage CD, are fed to an error unit UP serving to advance the test program, where they are examined and interpreted. The three recipients Ric-, Rio «! Ric, are connected to lines V _& and V ₀ via switches I., Ic and Ig, respectively. The first two of these switches are actuated by the phase signal ^ *, while the third, ie switch Ig, is actuated by the phase signal JuT ₀₂ .

The test device uses the same logic circuits of the processing or operating unit UC with which the switches of the subscriber group to be tested are operated. The number is written in the service phase selected for the test, in this Pail in phase 0q * $ in the memory of the called subscriber (or that of the calling subscriber) registered in the phase $ q ^ of the memory of the calledea numbers

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. 1961728

is when it _{receives a signal A 1} at the input and at the same time a signal P ^ from the unit UO. _{The signal A 1} indicates that none of the subscribers does not have to send the ringing stream. The signal P indicates that the number that was transferred to phase 0 ** of the memory of the called numbers is not included in any of those for telephone traffic is written in certain phases, either in the memory of the called numbers or in that of the "calling numbers" _. that no participant will be sent a Hufatroffi mv & _{f a signal F ß is} delivered by the unit UG durcii. This signal is stored in a two-stage SoMetseregister IE _f and j becomes effective when the Versohiebimgssignal 0 _Q ~ it in the second stage transmits _t wherein the signal A ^ already mentioned is generated. The signal A- eriefLt the unit UP approval to carry out * the test attempts and at the same time controls a transistor Tr in the conductive state, so that a relay E connected in series with this transistor picks up, the contact r of which couples the generator GH to the line Y _ß .

The tests are checked or «carried out one after the other by the unit ΈΒ. The sickle UP works during the phase Ot on the basis of the plias synchronization signal 0q * _f that it receives from the inline UP. The control of the generator GE duroli the unit UP is carried out by the following signals

Command? ^ R Sending the SOO Es - Sonsigoals command to interrupt d.33 89 · ΐ> Hs - Tonsigaals to simulate the XfnteTor3üh \ mg- dea (Zweileltungs—} SignalieierungsstroiBS *

The lisSieit UC is also controlled by the

Unit UP through the following signals »

A ° _K = consent to the transmission of a signal AK1 through which the unit UC _{causes the switch I 1 to} close (it is assumed that the subscriber group A ^ is checked);

H ⁰ = consent to the transmission of a signal M-, as a result of which the unit UC causes the switch X to close;

A ° "= agreement to send a signal A ^, whereby the unit · UC closes switch I «.

In the event of damage or a malfunction, the UP unit generates an alarm signal AI ₁ , AI ₂ , AI or AI., Depending on the type of malfunction found. The alarm signals, which correspond to disturbances which could spread, as well as signals K ₁ ... K _n are applied to a blocking unit UI. The signals K ₁ ... K _n , each of which corresponds to a specific group of subscriber groups, inform the unit UI about the group that is being checked at the respective time. The unit UI sends the unit UC signals Ap ₁ ... A "to block or suppress corresponding signals K ₁ ... K _n (represented by K _ß ), with which the unit UC closes the disconnectors in groups 1 η (in Pig. 1 of group h)

causes. Accordingly, the signal A ^ prevents the transmission of the signal K _h , which causes the switch I _? and I _{would cause 8} , thereby excluding group h from lines V and V.

a 8

There are no specific punctures of the UP test unit logical combination circuits in addition to those of the

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Unit UC required. In a switching system, in the one linkage holding with a circulating memory is provided who controls the program after the necessary switching connections on each time channel are carried out, it is very useful to use this memory in phase 01 for that controlled by the UP unit To use the test program. In addition, if there is a service phase of the memory of the called numbers or that of the numbers of the calling subscribers in connection with a logic combination circuit is used to build a counter that counts the

P should control cyclical scanning of all subscriber lines to determine their current status, see above the logic circuit of this counter can be used in the PL- phase to implement the tests required Counter can be used. This results in a significant simplification of the circuit arrangement. These two requirements are in an electronic known from Italian patent specification no. 824.625 Switching system met, in which the invention with the logic combination unit shown in FIG UP is realizable. As shown in FIG. 2, the operating unit contains UC of the switching system a memory N, the called subscriber with

"a logic combination circuit RN, which forms a counter with a service phase of the memory N, which has the task of controlling the operation of the cyclical sampling of the DC state on the lines of all subscribers connected to the switching center. The unit UC also contains a memory P, in which the various work processes for connecting two participants are registered

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the Italian patent specification Hr, 810.709 is known.

The work processes of interest here are the zero setting, which is caused by the application of a signal an input T of the circuit RF is effected and the count (in accordance with a phase of the Memory P) of the impulses that appear at another input C of the circuit «line logical connection ·

circuit R .. of the unit UP carries out the test program in connection with the memory P and the logic circuit RP through.

In phase 01 of the memory P, the identification numbers of the various test attempts are stored, which are converted into signals Du, D-, .. D- by a decoder dec as soon as they appear at the output of the memory P. An AND gate 1 initiates the test program when the memory P is set to zero in accordance with the phase and when it receives a signal F, which indicates that the participant whose lobster is written in phase 01 of the memory N, there is no conversation. By means of further USD-GIieder 2, 3, and continues the test program or "pushed further ¹¹ if the previous test is positive. If the output of the AND gates 1, 2, 3 ₉ 4 a signal from the binary value" one "appears generated an OR element 5 connected upstream of them sends a signal of the value "Bins", which advances the counter implemented with the circuit RP and phase 01 of the memory P. An O element 7 causes, via an upstream OR element 8, that the counter is set to Hull, "if the last attempt also ran with a positive result. The OR gate 3 also delivers a zeroing signal when it _{receives a signal D x} coming from the encoder, which is then generated when

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there is a number in memory P which does not belong to those which were selected to identify the various test attempts. By means of the OR gates 5 or 8 upstream AND gates 6 or 9, it is achieved that the signals for advancing the test program and the test position signal are only effective in phase O1 (then when the signal pL .. has the binary state "One"), namely periodically when clock signals M appear, which also cause the above-mentioned receivers to generate _{the signals S 1, S 2 and S 1 at the respective time.}

At the first test, which was _{initiated by signal D 1 of} the decoder, the OBSR- (JIieder 10, 11, a logic combination circuit R "of the test unit UP _generate the signals M ° csP G ^ and S _g . They signals A ° _K and Α ° _ρ are missing, so that the switches of the subscriber circle cannot close.The test is positive if the sound signal of 800 Hz and the signal for simulating the signaling current do not appear on the voice line or the signaling line.

If the signal D «appears at the output of the decoder, which corresponds to the second test attempt, the signals

cB 1 ° l? ^erzeu Sfr · If the group of participants is perfect, the receiver Ric _o must receive the audio signal of 800 Hz via the line V ", while the receiver RiC _{5 must} not receive any Xon signals that exceed the permissible crosstalk level. When the signal D, which corresponds to the third test attempt, appears, the signals M ° _CB and Gg are generated. The group of participants is only correct if the receiver Rio., Not via the Signalieiemingsleitung V ^ receives the signal to simulate the Signalisierangsstromaa. When the signal D, which corresponds to the fourth test signal, appears, the signals M ° _CB , Gg xsnd A ° _{K are} generated. In this pail, with faultless

free group of recipients Ric. the simulation signal of the signaling stream received.

Another logic combination circuit R3 of the unit UF receives the signals S. _f S ₂ and S at the input and receives information about the test carried out by the signals Dj, D ₂ , D, and D ^. The logic circuit R3 generates an alarm signal if the test attempt is negative. In detail, an AND element 15 supplies an alarm signal AI ₁ when it receives the signal S or the signal S ₀ on the basis of the first test, which is logically supplied by an OR element 13

C. ·

can be summed up. An alarm signal AI ₂ is generated by an AND element 16 when it receives the signal S * or the signal S, which are logically eumaiert by an OR element 14, as a result of the second attempt. An AND gate 17 generates an alarm signal AI, if it tries the signal S ₄ in the third test. receives, and finally a logic element 18 generates an alarm signal AI., if during the fourth test attempt (D ^) da3 signal S ₁ . does not appear.

These different alarm signals can be used to determine the type of damage or fault in question. A lobster signal U "to identify the group of participants it is periodically delivered to the output of the memory N. 'Both the defective or disturbed subscriber groups as well as the type of damage bind so immediately recognizable. When the test attempts for a participant are completed, which is indicated by the output signal of an AND gate 19, enables the logic circuit As a rule, the advancement of the counter implemented by phase 01 of memory N. The exit signal of the AND gate 19 is only allowed through by a further AND gate 20 when this

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is gated by the signal A., which says that for no one. Subscriber set the transmission of the ringing stream is requested.

The blocking unit TJI shown in Fig. 3 is used to generate a signal A ^ ₁ that prevents the closure of the switches connecting the lines V ^ and V ₈ J ₁ to the corresponding central lines V or V_,

et B

_{if one of the alarm signals AI 1} , AI »» AI is generated during the tests of a group of participants in group h. The output signal of an OR element Z ₁ , which is generated when one of these alarm signals appears, arrives at the input of a series of logic circuits, one of which is provided for each subscriber group. Each of these logic circuits contains a bistable circuit F- ··· F, which stores the condition for each sample or sampling cycle of the time division multiplex system as to whether the switches of the corresponding subscriber group must be closed or open. The information stored in the bistable circuits is available as the signals Aj ₁₁ ... A _Rn for the unit UC. The general bistable circuit Fj ₁ , which is reset to zero at the beginning of each sampling cycle of phase signal 0q * , changes its state when an alarm signal appears at the output of OR gate Z * and at the same time in accordance with phase 01, i.e. when the Signal 0Q <t the signal Kj ₁ indicates that the subscriber group to be tested belongs to group h. This bistable circuit also changes its state when the participants eu tested · is not one hour to the group The first condition is _n from a UHD GIied X. X, so here X ^ met, while the second condition of a logic gate Y.. ..Y _n or Yj ₁ , which is a UHD element with a negated input, is implemented. The output signals of these two AND gates are keyed

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an OR gate O ₁ ... O ₁ O j _n and the bistable circuit _f1. . · F "or F ₁ ..

Claims (1)

PATENT CLAIMS Circuit arrangement for the automatic checking and detection of faults in the subscriber groups of a time division multiplex telephone exchange, which has two circulating memories in a central operating unit, which store the number of the calling or that of the called subscriber and, in the corresponding subscriber groups, the closing of the subscriber group with a common one Control voice line and a common signaling line connecting switch, and which also contains a generator that sends a ringing current to a ringing current line common to all subscriber circuits, which is fed to the subscriber circuits via separate switches, as & urek characterized that a test signal generator (& H) _f of a tone frequency Test signal generated, coupled with the ringing current line (V), if no subscriber set (U ..) requests the transmission of the ringing current! that serves to Weitei'sciialttrag a test program testing unit (UP) of the auswüilt each to be tested group of participants (^ Tj-J), controls the Prüfeignalgenerator and interrupts its Aiisgacgssignal such that been simulated Zustandsändenragem üs & Zveileittrags signaling current, and in accordance with a Menstssitkanal (fe) dia closure -unä. Opening the switch controls that of the audited group of participants with the HafstroHleitüsg, 'ler Spreehleitrag (V ^, Y) and. der SigmelieieniiagsleitTjsag (V ₈ J ₁ , V) connect j 1 § S 5 ΐ * ^s "ί 11 ύ ORIGINAL INSPECTED 196172S and that a receiving unit (UR) the signal level Controlled on the voice line and the signaling line and output signals to the test unit sends, which generates an alarm signal (AI) when a fault is detected. Circuit arrangement according to Claim 1, characterized in that the checking unit (UP) contains a logic combination circuit (H4) which is connected to a service phase (h) of the memory (N) for the called numbers or the memory for the lobsters of the calling subscriber forms a counter which is incremented at the end of each test cycle if an information signal (A.) reports that a call stream is not to be sent to any subscriber in the switching system is; and that through the content of this counter, which registers the numbers of all subscribers one after the other, the switches are operated in the corresponding subscriber group by means of the circuits already prepared in the operating unit (UG) of the switching system are determined by the control signals sent by the test unit (UP) to the operating unit. Circuit arrangement sun automatic control check and Detection of faults in the subscriber groups of an electronic time-division switching system, in particular according to Claim 1, characterized in that the control of the test cycle in the test unit (UP) is carried out by a logic combination circuit (R1) which is associated with a phase (h) of a Circulating memory (P) cooperates, which is already available in the switching system to carry out other functions, that successively identification numbers of the various test attempts are stored. 109809/1210 1961723 Circuit arrangement, in particular according to claim 1, for the automatic checking and detection of faults in the subscriber circuits of a time division multiplexing system, in which all subscriber groups are divided into groups, each of which has a group intercom line and a group signaling line and switches controlled by τοη an operating unit of the switching system with the other groups can be connected when a participant of the group is conducting a call, characterized in that the test unit (UP) generates different alarm signals (A1) when carrying out different types of tests for different types of faults; that the alarm signals, which are based on disturbances that could affect the overall operation of the switching system, reach a blocking unit ■ (UI) which prevents the switch (I-, I ₈ ) in the operating unit (ITC) from being closed, which the separate the disturbed subscriber group from the other groups; that this blocking unit (Ul) contains a memory circuit (F ₁ ... P) and a logic combination circuit (0, X, Y) for each subscriber group, which transmits the received alarm signals (Al) to the memory circuit of that subscriber group that the operating unit ( UC) asle the checked subscriber group group is designated} and that this alarm signal writes the information about the prevention of the closure of the switch in the memory circuit, which is deleted at the beginning of each sampling cycle of the time division multiplex system. 109800/1210